The present invention relates to a roller of a support arrangement for a rotary milking platform, wherein the support arrangement comprises a first rail member fixedly connected to the rotary platform, a second rail member stationarily arranged in a position below the platform, and a plurality of rollers arranged in a vertical space between the first rail member and the second rail member, wherein said roller is one of said plurality of rollers, and comprises a peripheral surface to be in contact with a contact portion of the first rail member and a contact portion of the second rail member. The roller rolls on the stationary second rail member at the same time as it supports and provides a rotary motion of the first rail member and the platform above the stationary second rail member. The roller is a support roller which forms an underlying support of the platform. The support rollers of the support arrangement are to support the whole weight of the platform and the animals on the platform during a milking process.
Conventional support arrangements for rotary milking platforms comprise rollers with cylindrical contact surfaces rolling along a substantially flat contact surface of a rail member connected to the platform. The rollers may be provided with flange portions. In this case, the support arrangement comprises rollers which rotate around a respective horizontal axis such that they form a vertical support of the platform at the same time as the flanged portions provide a positioning of the platform in a horizontal plane. A support arrangement comprising rollers without flange portions includes support rollers which rotate around a horizontal axis and side rollers which rotate around a vertical axis. The support rollers form a vertical support of the platform and the side rollers provide a horizontal positioning of the platform.
A rotary milking platform supporting cows is heavy and the load on the rollers is high. The rollers are many times manufactured by a plastic material such as nylon. Especially the side portions of the contact surface of the rollers may become worn out. The side portions of the contact surfaces can start to crack and parts of them can fall off. Furthermore, it is difficult and time consuming to exchange worn out rollers supporting a rotary milking platform.